Draftsman s triangle and protractor



(No Model.)

' L. W. STOGKWELL.

DRAFTSMANS TRIANGLE AND PROTRAGTOR. No. 246,045. -Patented Aug. 23,1881.

llll ll,ll ll bi/m mam UNITED STATES PATENT OFFICEO LE VI W. STOGKWELL,OF CLEVELAND, OHIO.

DRAFTSMANS TRIANGLE AND PROTRACTOR.

SPECIFICATION forming part of Letters Patent No. 246,045, dated August23, 1881,

Application filed January 10, 1881. (No model.

To all whom it may concern Be it known that I, LEVI W. .S'rocKWELL, ofthe city of Cleveland and State of Ohio, have invented a new and usefulImprovement in Drawing Implements, of which the following is aspecification.

The natureot' my invention is arulerforming a right-angled triangle,except at a hingejoint at the end of one side connect-ingit with a partof the hypotenuse, which turns on the joint at one end and at the otheris movable forty-five degrees on a protractor.

In the drawing forming a part of this specification, the figure is aplan.

The sides a and b and the side or hypotenuse d d are each of suitableWidth and thickness for a ruler. Sides ab form a right angle with eachother at a, and are at an angle of fortyfive degrees with the side (I d.The protractor e is an are extending from the inside right angle at n tothe hypotenuse d d. Its radius cl is a part of the side d d, and isconnected at one end with side a by an ordinary knucklejoint, 0, theother end being grooved to slide on tongues of the protractor e. Thesides are marked with a scale of inches and the protraetor with a scaleof degrees. When the radius d has been turned on protractoreto anydesired angle with side a, and a line has been drawn at its side, bychanging the position of 30 the instrument and putting side bin theplace of side a the radius (1 will be at right angles to the line sodrawn. In whatever position radius d is turned on protractor 6 its angleto side I) will be the difference between its angle to side a and ninetydegrees.

I claim as my invention As an article of manufacture, a drawingimplement having the sides a b at right angles to each other and at anangle of forty-five degrees to the side d d, and the protractor e,havingfor its radius d a part of side (I (1, connected by joint 0 withside a, and sliding on the protractor when turned on the joint,substantially as described.

7 LEVI W. STOOKWELL.

Witnesses:

LEWIs W. FORD, W. A. BIDDLE.

